Shift-by-wire fail control device for vehicle with automatic transmission

Abstract

A shifting apparatus includes an actuator to direct a travel range setting of a vehicle transmission, a selector to indicate a desired travel range setting, a transmission controller to move the actuator into the travel range setting in response to the desired travel range setting of the selector, and a restrictor to restrict an output of a drive motor if the vehicle transmission is in a travel range setting other than the desired travel range setting. A method to control a vehicle transmission includes detecting a travel range setting of the vehicle transmission, detecting a desired travel range setting of a selector, and entering a limp-home mode if the detected travel range setting is different from the desired travel range setting and a detected vehicle travel direction corresponding to the detected travel range setting is the same as a desired travel direction corresponding to the desired travel range setting.

What is claimed is: 
     
       1. A shifting apparatus of a vehicle transmission, the shifting apparatus comprising:
 an actuator to direct the vehicle transmission into a travel range setting; 
 a selector to select a desired travel range setting; 
 an actuator detector to output the travel range setting of the actuator to a transmission controller; 
 a selector detector to output the desired travel range setting of the selector to the transmission controller; 
 the transmission controller to move the actuator into the travel range setting in response to the desired travel range setting of the selector; 
 a restrictor device to restrict an output of a drive motor if:
 failure of a shift-by-wire system is detected, 
 the desired travel range setting determined by the selector detector is within a travel range, and 
 a vehicle travel direction corresponding to the travel range setting detected by the actuator detector is the same as a desired vehicle travel direction corresponding to the desired travel range setting detected; and 
 
 a shut-off device to stop an output of the vehicle transmission if the desired travel range setting is within the travel range and if the vehicle travel direction corresponding to the travel range setting detected by the actuator detector is opposite from the desired vehicle travel direction corresponding to the desired travel range setting, 
 wherein the travel range corresponds to a forward travel range (D) and a reverse travel range (R). 
 
     
     
       2. The shifting apparatus of  claim 1 , wherein the actuator comprises a manual valve. 
     
     
       3. The shifting apparatus of  claim 1 , wherein the travel range setting of the actuator is one of a park range (P), the forward travel range (D), the reverse travel range (R), and a neutral (N) range. 
     
     
       4. The shifting apparatus of  claim 1 , wherein the desired travel range setting of the selector is one of a park range (P), a forward travel range (D), a reverse travel range (R), and a neutral (N) range. 
     
     
       5. The shifting apparatus of  claim 1 , further comprising a shut-off device to stop an output of the vehicle transmission if the actuator detector outputs a travel range setting corresponding to a vehicle travel direction that is opposite from a desired vehicle travel direction corresponding to a desired travel range setting outputted by the selector detector. 
     
     
       6. The shifting apparatus of  claim 5 , wherein the restrictor device is configured to shut off the output of the drive motor if the vehicle travel direction is opposite from the desired vehicle travel direction. 
     
     
       7. The shifting apparatus of  claim 1 , wherein the transmission controller comprises an electrical link between the actuator and the selector. 
     
     
       8. The shifting apparatus of  claim 1 , wherein the transmission controller comprises a hydraulic link between the actuator and the selector. 
     
     
       9. The shifting apparatus of  claim 1 , wherein the transmission controller comprises a mechanical link between the actuator and the selector. 
     
     
       10. The shifting apparatus of  claim 1 , wherein the vehicle transmission is a continuously variable transmission. 
     
     
       11. A method to control a vehicle transmission, the method comprising:
 detecting a travel range setting of the vehicle transmission; 
 detecting a desired travel range setting of a selector; 
 detecting whether a shift-by-wire system failure has occurred; and 
 entering a limp-home mode allowing a restricted output of a drive motor only if:
 failure of the shift-by wire system is detected; and 
 a detected vehicle travel direction corresponding to the detected travel range setting is the same as a desired travel direction corresponding to the desired travel range setting, 
 
 wherein the travel range corresponds to a forward travel range (D) and a reverse travel range (R). 
 
     
     
       12. The method of  claim 11 , further comprising entering a fail-safe mode if the detected vehicle travel direction is opposite from the desired travel range setting. 
     
     
       13. The method of  claim 12 , wherein the fail-safe mode comprises shutting off torque output of the vehicle transmission in both a reverse and a forward direction. 
     
     
       14. The method of  claim 12 , wherein the fail-safe mode comprises shutting off torque output of the vehicle transmission in one of a reverse and a forward direction. 
     
     
       15. A vehicle including a drive motor and a vehicle transmission, the vehicle comprising:
 an indicating means for indicating a desired travel range setting; 
 a detecting means for detecting a travel range setting of the vehicle transmission in response to the indicated desired travel range setting; and 
 a restricting means for restricting an output of a drive motor if:
 failure of a shift-by-wire system is detected, 
 the directed travel range setting is within a travel range, and 
 a vehicle travel direction corresponding to the travel range setting detected by the detecting means is the same as a desired vehicle travel direction corresponding to the desired travel range setting detected; and 
 
 a shut-off means to stop an output of the vehicle transmission if the desired travel range setting is within the travel range and if the vehicle travel direction corresponding to the travel range setting detected by the detecting means is opposite from the desired vehicle travel direction corresponding to the desired travel range setting, 
 wherein the travel range corresponds to a forward travel range (D) and a reverse travel range (R).